The size of radios, meaning combined transmitters and receivers, has been steadily decreasing so that their use, for instance, in RF tags is now commonplace. It will be appreciated that each RF tag has a single small or miniature radio that in general costs approximately 50 cents. All of these RF tags are meant to be used to tag items and to be able to detect the items when they pass through a checkpoint. The costs of such tags and applications for even smaller tags give rise to the possibility of a large number of applications should, for instance, the radios be implementable well below a cubic millimeter in size and more particularly down to a 10-micron cube.
Moreover, the power output of such single microradios leaves something to be desired inasmuch as single microradios are limited in output power, especially when using parasitic powering schemes. Moreover, in order to parasitically power such miniature radios one needs supercapacitor technology involving high energy density capacitors fabricated in a regular pattern with a large surface area per volume.
It will be appreciated that if the microradio needs to have a given power output to obtain a given range, then the range is severely limited both by the ability to provide supercapacitors or, if a battery is carried on board, then the size of the miniature radio is prohibitively large.
Were it possible to make large numbers of microradios in the 10-micron size range and were it possible to distribute these radios across an area; and further if the radios could be accessed so as to provide their outputs in a coherent fashion, then the distributing of these radios over a given area would have an n2 power advantage such that if it were possible to manufacture, code and distribute 1,000 radios in a given area, one would have a million more times the radiated power.
By causing each of the radios to coherently radiate, one can increase range or concurrently decrease the need for tuning each of the radios to their antennas. There is therefore a benefit in providing an ensemble of a large number of miniature radios from the point of view of, for instance, being able to detect the radios at 10,000 kilometers or better, such as by satellite.
The ability to produce hundreds of thousands or millions of radios at a time not only is important to reduce the cost of the radios from, for instance, 50 cents per radio to $1.00 per million radios, it is also important that one be able to utilize non-high density capacitors that presently exist in order to power the miniature radios parasitically. Because batteries cannot be made sufficiently small, one requires that a microradio be powered parasitically, meaning that energy that is available from the environment is captured on a capacitor, where it is rectified and utilized to power the transceiver.
Thus it would be desirable to provide a parasitically powered microradio, parasitically coupled to some decent antenna, with the microradio having its own microantenna.
Even in the case that each radio is not particularly well-tuned to whatever antenna it is using, the ability to produce large numbers of extremely inexpensive microradios and randomly distribute them across a surface that could function as an antenna could result in at least a large portion of the miniature radios being located at the feedpoint of whatever antenna is available. Thus, if one can distribute the radios across a surface in some random fashion, then the probability of there being a microradio at an antenna feedpoint is large for at least a certain percentage of the distributed radios.
Thus if it were possible to manufacture millions of microradios inexpensively and distribute them across a surface, and assuming the surface had some natural antenna such as a slot in a metal object, or the dielectric as provided by the human or an animal body and the salt therein, or a ferromagnetic body, then one could obtain a sufficiently usable signal that could be detected anywhere from numbers of feet to many thousands of kilometers away, even with the minute power outputs from each of the individual microradios.
As a further consideration of power it will be appreciated that if the transmit cycle for the radio could be reduced to a small portion of a prolonged charging cycle, then it would be possible to deploy such numbers of microradios without concern about power. This is due to the relatively long charging time available for the capacitors utilized for each of the microradios versus the short amount of time necessary to transmit information.
Moreover, were it possible to reliably manufacture such microradios on a very large scale, there are applications in tagging and authentication as well as anti-piracy and medical applications for which such tiny microradios or ensembles of microradios could be used.